All posts tagged with websocket

HTML5 RDP Client

April 05, 2017 - Søren Alsbjerg Hørup

The Remote Desktop Protocol (RDP) is a protocol used for remote desktop connections primarily against PC’s running Windows, or VMs in the Azure cloud. The protocol is similar to VNC in many ways.

The HTML5 application I am currently building required the ability to seamless connect to a desktop computer using RDP. HTML5 however does not support RDP and cannot easily be implemented in the browser due to:

  • HTTP cannot be used for cross-domain connections.
  • WebSocket is not implemented by the remote PCs that I need to connect to.

The solution I found was to “tunnel” an RDP connection through the server hosting my HTML5 application. Several solutions exists, one being: Myrtille.

Myrtille is basically an ASPX application hosted in IIS, which provide a WebSocket interface and HTML5 remote desktop client (it also support HTML4 using HTTP which is slower). Myrtille, upon getting a connection request from a web client, tunnels the request back and forth through a Gateway service which comes with Myrtille.

The gateway utilizes a free implementation of RDP callsed FreeRDP, specifically wfreerdp.exe on Windows. The gateway service spawns a wfreerdp.exe process which does the actual RDP connection to the remote desktop computer.

When the connection is made, mouse and keyboard input is sent from the HTML5 client in the browser, through Myrtille to wfreerdp. Image data is transmitted from wfreerdp back to the HTML5 client.

[caption id=“attachment_1150” align=“alignnone” width=“1168”] rdp.png The RDP client in action running inside my Chrome browser[/caption]